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Fuel Injector Circuit

CAUTION:
  • Check or repair only faulty parts.
  • After repairing or replacing the defective part, carry out the Clear Memory Mode <Ref. to OPERATION  CLEAR MEMORY MODE. > and Inspection Mode <Ref. to PROCEDURE  INSPECTION MODE. >.

WIRING DIAGRAM: 

Fig 1: Identifying Fuel Injector Circuit - Wiring Diagram
G04993041
DIAGNOSTICS PROCEDURE CHART

Step Check Yes No
1 CHECK OPERATION OF EACH FUEL INJECTOR. 
While cranking the engine, check that each fuel injector emits the "operating" sound. Use a sound scope or attach a screwdriver to the injector for this check.		 Does the fuel injector operate? Check the fuel pressure. <Ref. to INSPECTION Fuel Pressure. > Go to step 2. 
2 CHECK POWER SUPPLY TO EACH FUEL INJECTOR. 
  1. Turn the ignition switch to OFF.
  2. Disconnect the connector from fuel injector.
  3. Turn the ignition switch to ON.
  4. Measure the power supply voltage between fuel injector terminal and engine ground.

    Connector & terminal 

    #1 (E5) No. 2 (+) - Engine ground (-): 

    #2 (E16) No. 2 (+) - Engine ground (-): 

    #3 (E6) No. 2 (+) - Engine ground (-): 

    #4 (E17) No. 2 (+) - Engine ground (-): 

 Is the voltage more than 10 V? Go to step 3.  Repair the harness and connector.
NOTE: In this case, repair the following item:
  • Open circuit in harness between main relay and fuel injector connector
  • Poor contact in main relay connector
  • Poor contact in coupling connector
  • Poor contact in fuel injector connector
3 CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 
  1. Disconnect the connectors from ECM.
  2. Measure the resistance of harness between ECM and fuel injector connector.

    Connector & terminal

    m (B137) No. 8 - (E5) No. 1: 

    #2 (B137) No. 9 - (E16) No. 1: 

    #3 (B137) No. 10 - (E6) No. 1: 

    #4 (B137) No. 11 - (E17) No. 1: 

 Is the resistance less than 1 Ω? Go to step 4.  Repair the harness and connector.
NOTE: In this case, repair the following item:
  • Open circuit in harness between ECM and fuel injector connector
  • Poor contact in coupling connector
4 CHECK HARNESS BETWEEN ECM AND FUEL INJECTOR CONNECTOR. 
Measure the resistance of harness between ECM and fuel injector connector.

Connector & terminal 

#1 (B137) No. 8 - Chassis ground: 

#2 (B137) No. 9 - Chassis ground: 

#3 (B137) No. 10 - Chassis ground: 

#4 (B137) No. 11 - Chassis ground: 

 Is the resistance more than 1 MΩ? Go to step 5.  Repair the ground short circuit of harness between ECM and fuel injector connector.
5 CHECK EACH FUEL INJECTOR. 
  1. Turn the ignition switch to OFF.
  2. Measure the resistance between each fuel injector terminals.

    Terminals 

    No. 1 - No. 2: 

 Is the resistance between 5 and 20 Ω? Go to step 6.  Replace the faulty fuel injector.
6 CHECK POOR CONTACT. 
Check poor contact of ECM connector.		 Is there poor contact in ECM connector? Repair poor contact in ECM connector. Inspection using "General Diagnostic Table" <Ref. to INSPECTION  GENERAL DIAGNOSTIC TABLE. >
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